*Alternative diagnoses may include evidence of acute liver disease due to other causes or advanced liver disease due to hepatitis B reactivation (see section VIB), pre-existing chronic HBV infection, other causes including alcohol exposure, other viral hepatitis, hemochromatosis, or conditions known to produce false positives of hepatitis B surface antigen, etc.
A2. Laboratory Criteria**
Confirmatory Laboratory Evidence:
Acute HBV Infection:
Tier 1
Detection of HBsAg† AND detection of IgM anti-HBc, OR
Detection of HBeAg AND detection of IgM anti-HBc,OR
Detection of HBV DNA†† AND detection of IgM anti-HBc, OR
Detection of HBsAg,† HBeAg, or HBV DNA within 12 months (365 days) of a negative HBsAg test result. (i.e., HBsAg seroconversion)
Tier 2
Detection of HBV surface antigen (HBsAg)† AND IgM antibody to HBV core antigen (IgM anti-HBc) test not done or result not available, OR
Detection of HBV DNA†† AND IgM anti-HBc test not done or result not available
Presumptive Laboratory Evidence:
Acute HBV Infection:
Detection of IgM anti-HBc, AND
Negative or not done for HBsAg, HBV DNA, or HBeAg
**Note: The categorical labels used here to stratify laboratory evidence are intended to support the standardization of case classifications for public health surveillance. The categorical labels should not be used to interpret the utility or validity of any laboratory test methodology. † If information on HBsAg test method is available and HBsAg confirmatory neutralization was performed as recommended, HBsAg positive by confirmatory neutralization. †† DNA detection by nucleic acid test, including qualitative, quantitative, or genotype testing.
A3. Epidemiologic Linkage Criteria
N/A
A4. Case Classifications***
Confirmed:
Acute HBV Infection
Meets Tier 1 confirmatory laboratory evidence of acute HBV infection, OR
Meets clinical criteria AND Tier 2 confirmatory laboratory evidence of acute HBV infection.
Probable:
Acute HBV Infection
Meets clinical criteria AND presumptive laboratory evidence of acute HBV infection.
***Individuals born in the US, under or equal to the age of 24 months, and born to a mother with documented evidence of hepatitis B infection should be reporting using the Perinatal Hepatitis B Position Statement (16-ID-06), unless there is evidence that exposure occurred via a non-perinatal mechanism (e.g., healthcare acquired).
B. Criteria to Distinguish a New Case of Acute or Chronic Hepatitis B from Reports or Notifications which Should Not be Enumerated as a New Case for Surveillance
A case of HBV infection classified under the Perinatal HBV position statement (16-ID-06) can be additionally enumerated as a confirmed case of chronic HBV infection if a positive HBV viral detection test (HBsAg, HBeAg, or HBV DNA) is obtained after the case is greater than 24 months of age.
A confirmed acute case of HBV infection may be additionally enumerated as a new confirmed chronic case of HBV infection if a positive HBV viral detection test is reported 6 months or longer after acute case onset or, if asymptomatic, after the initial positive test result.
An acute case of HBV infection should not have been previously enumerated as a case of either acute or chronic HBV infection.